This application makes reference to, incorporates the same herein, and claims all benefits accruing under 35 U.S.C. xc2xa7119 from my application PAPER EXTRACTING APPARATUS FOR PRINTING DEVICE filed with the Korean Industrial Property Office on Jan. 22, 2001 and there duly assigned Ser. No. 3583/2001.
1. Technical Field
The present invention relates to a paper discharging apparatus for a printer designed to prevent damage to a sheet of paper so that the sheet of the paper can be stably stacked.
2. Related Art
A conventional star wheel type paper discharging apparatus includes a plurality of star wheels installed in a row and at predetermined intervals. Each star wheel has a ratchet formed along an outer circumference thereof so that the star wheels catch a sheet of paper while rotating. A discharge roller has a plurality of grooves formed thereon to correspond to each ratchet so that the discharge roller can discharge the paper while rotating in contact with the star wheels.
In the prior paper discharging apparatuses, when paper is discharged between the star wheel and the discharge roller, a trace of the ratchet is generated on the paper, thus damaging the paper so that the quality of print is lowered. In addition, paper passing through such paper discharging apparatuses is not stably stacked.
Certain paper discharging apparatuses employ wings for guiding paper discharged by a holder so that the paper is stacked in a stable manner. However, in such paper discharging apparatuses, since a print head transfer mechanism must be moved to a power transfer apparatus to operate the holder and the wings, the speed of print is lowered.
Arrangements to solve the above problems have been made or suggested, but such arrangements present additional problems. For example, such arrangements cause an increase in the bottom margin of the paper where printing is not possible.
To solve the above problems, it is an object of the present invention to provide a paper discharging apparatus for a printer in which a paper discharge holder and a support plate are operated by using a crank rod and a cam shaft so that sheets of printed paper are discharged with no damage and the papers can be stably stacked in a printing apparatus.
Accordingly, to achieve the above object, there is provided a paper discharging apparatus for a printer comprising: a plurality of support plates for supporting the paper installed at both sides of a paper proceeding direction at a base frame, and rotating in a direction parallel to the paper proceeding direction; a rotation shaft of a feed roller arranged in a direction perpendicular to the paper proceeding direction, a feed roller contacting the paper being coupled to the rotation shaft; a power transfer portion having a sector gear installed on the rotation shaft of the feed roller so that the sector gear does not rotate when the rotation shaft of the feed roller rotates in a forward direction, but does rotate when the rotation shaft of the feed roller rotates in a reverse direction; a crank rod having one end connected to the sector gear and reciprocating when the sector gear rotates; a cam shaft connected to the crank rod and rotating in correspondence to the reciprocation of the crank rod, a cam being connected thereto for performing interference movement with respect to the support plates; and a holder engaged with the rotation of the cam shaft and having a plurality of kickers for pushing the paper toward the support plates. In accordance with the invention, when the sector gear rotates in the forward direction, the paper is supplied or printed, and when the sector gear rotates in the reverse direction, the holder is engaged with the cam shaft, performing angular movement, by the crank rod connected to the sector gear so that the end portion of the paper is pushed, and the paper is supported by the support plate, and dropped downward and stacked.